TR8I-2 MICHIGAN DEPARTMENT OF NATURAL RESOURCES Fisheries Division Technical Report: No. 81 -2 AprilI, 1981 STATUS OF TIGER MUSKELLUNGE MANAGEMENT IN MICHIGAN William MeClay, Lake Management Specialist SUMMARY Muskellunge are important predators in the fish community and are considered by many anglers to be the "big game trophy" of freshwater angling. Populations diminished in Michigan by the mid-1950's, at which time efforts were initiated to develop natural, self-sustaining populations. In the mid-1960's, cultural techniques were developed to produce the hybrid tiger muskellunge, which was seen as a way to increase musky fishing opportunity througlh maintenance stocking. Michigan's muskellunge program presently has an economic impact to the state of about $6 million. The hybrid tiger, musky is present in 141 inland lakes in 54 of Michigan's 83 counties. Almost half are located in Southern lower Michigan where fishing demand is the greatest. Public acceptance of the musky program has been generally good, but some concern has been expressed by the public for the impact tiger muskellunge could have on other fish populations. However, thus far there is no evidence that tiger musky have had any significant detrimental effect on other fish populations. STATUS OF TIGER MUSKELLUNGE MANAGEMENT IN MICHIGAN William McClay, Lake Management Specialist INTRODUCTION History of Tiger Muskellunge Northern pike and muskellunge are important predators in the fish community and popular game fish in many North American lakes. Fisheries managers consider them to be valuable in maintaining desirable game fish populations. Anglers regard the musky even more highly than the northern pike and many consider them to be the "big game trophy" of freshwater angling (Graff, 1978). However, the natural range of muskellunge is restricted (Figure 1) and population densities are generally low. For these reasons, fisheries managers have often sought means of improving and/or expanding musky populations. North American fishery scientists presently recognize only one species of muskellunge (Scott and Crossman, 1973). However, three fairly distinct marking patterns exist over the normal range and have led to their being considered subspecifically as distinct populations. These are the Great Lakes musky (spotted pattern), the Ohio River Valley musky (diffusely spotted or barred), and the northern (Minnesota or Wisconsin) musky (barred or with no pattern). Figure 1. Geographical distribution of muskellunge in North America (Adapted from Scott and Crossman, 1973). A - 2 - The subspecies of principal interest in Michigan are the Great Lakes and northern muskies (Figure 2). Another Rame, the "tiger musky," has been associated with the purebred northern musky in Minnesota (Scott and Crossman, 1973). Presumably, this is because of the distinct pattern of dark, vertical bars located along the sides. More recently, the term "tiger musky" has been applied to the male northern pike x female northern musky hybrid which shows characteristics of both species, but a strong tendency toward dark, vertical barring (Figure 2). Hybridization between northern pike and muskellunge has been extensively reviewed by Beyerle (1973). The first naturally occurring hybrid was reported in Illinois in 1927. Hatchery production of this hybrid began in Minnesota and Wisconsin in 1939, in Pennsylvania in 1965, and in Michigan in 1966. Since that time, Ohio, New York, North Carolina, and Missouri have begun programs to culture and stock hybrid tiger musky. For the purpose of this report, further reference to the tiger musky will be in regard to this hybrid. Michigan's muskellunge program has been generallywell accepted statewide. However, in recent years some criticism has developed in a few areas (Iron Lake, Iron County; Grand Lake, Presque Isle County; and Upper Crooked Lake, Barry County). Some anglers have expressed fears that muskies would decimate game fish populations. And during 1979, one Michigan United Conservation Club (M.U.C.C.) affiliate introduced a resolution to their state convention which would have placed a moratorium on the statewide muskellunge program. M.U.C.Co tabled the resolution when Fisheries Division agreed to prepare a status report of the statewide muskellunge program. During 1980, field fisheries biologists were requested to analyze their muskellunge program and provide information on growth, survival, food habits, the sport fishery, impact on fish populations and public acceptance. History in Michigan Purebred muskellunge populations were once abundant enough to support a limited commercial fishery in the Great Lakes (Schrouder, 1973). They were widely associated with Great Lakes bays, major river systems, and drowned river mouths. However, by the mid-1950's, there were only about 15 lakes and streams where muskies produced a fishery (Williams, 1959, and Figure 3)., Efforts to halt the decline of native musky populations were initiated in 1955 (Scott, 1963), when emphasis was placed on the development of natural, selfsustaining populations. Experimental plantings of fry and fingerlings were made for the purpose of enhancing residual populations. In addition, introductory plants were made in 13 lakes in various locations throughout the state. Between 1955 and 1966, 339,000 fry and 92,000 fingerling purebred muskellunge were planted--an annual average of about 54,000 fry and 10,000 fingerlings during the years musky were releasted (Table 1). In the early 1960's, coincident with purebred musky production, hatchery personnel and managers began to consider the feasibility of culturing the tiger musky. The Tiger Muskellunye Figure 2. Marking ,tterns of the Great Lakes, northern, and tiger muskellunge. -4 - C-,45-v.-. 0 9i L Great Lakes muskellunge historical distribution (unpublished) / Northern muskellunge historical distribution (unpublished) Great Lakes and northern muskellunge distribution by 1959 (Williams, 1959) Figure 3. Distribution of muskellunge in Michigan - 5 - agricultural and poultry sciences had long before demonstrated increased vigor among hybrids. There was evidence that tiger musky showed superior growth and survival in the hatchery and that they could lend themselves well to the less expensive, intensive culture techniques (Hammond and Westers, 1981, personal communi cati on). Table 1. Purebred muskellunge plants in Michigan, Fish Planting Record and Scott, 1963). Year 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 TOTAL Fry 55,250 40,000 1955-1966 (Source: Annual Fingerl i ng 4,796 2,864 12,244 2,900 178,796 7,197 42,536 23,700 3,850 2,060 23,931 15,879 92,224 10,247 (9 years) 15,000 338,779 54,463 (6 years) Average Evidence gathered by various authors, and reviewed by Beyerle (1973), indicated that the tiger musky was, for all practical purposes, sterile. From that standpoint alone, it was an excellent prospect for management because the tiger musky would only be present so long as a stocking program was maintained in any given lake or stream. Michigan's tiger musky program was initiated in 1966 when four lakes were planted experimentally. As hatchery production levels improved and managers identified suitable waters, the program was slowly expanded (Table 2). Managers soon found that the tiger musky provided a new and exciting snort fishery. By 1980, -6 - Table 2. Muskellunge plants in Michigan, 1966-1980 (Source: Annual Michigan Fish Planting Record)o Purebred Muskyl Year Fry Fing. 1966 15,000 15,879 1967 50,000 70,706 1968 2,818 1969 3,470 1970 501 1971 10,450 1972 143,000 6,968 1973 40,000 2,779 1974 34,362 1,798 1975 50,000 6,064 1976 167,701 13,226 1977 19,725 1978 21,605 1979 64,217 1980 133,553 13,540 TOTAL 633,616 253,746 Average479,202 16,916 Tiger Musky2 No. of 3 Fing. Waters 3,652 4 11,578 10 3,528 3 28,013 7 49,848 9 49,298 11 26,601 30 9,978 10 31,762 24 21,891 14 93,997 46 107,194 51 128,542 62 136,235 79 251,607 96 953,724 141 63,581 Comments Pure strain not identified Pure strain not identified 987 were Great Lakes strain Pure strain not identified All Great Lakes strain Pure strain not identified 28 fing. were Great Lakes strain 20,520 were Great Lakes strain 14 were Great Lakes strain 38 were Great Lakes strain All purebreds were the northern strain except where noted under comments. 2 Intensive cultural techniques expanded to Platte River Hatchery beginning in 1976. 3 Number of waters planted represents the number of different waters planted from 1966-1980 and is not additive vertically. Averages are calculated based on the number of years that plants were made. m / - tiger musky had been stocked in 141 inland lakes totaling about 95,000 acres in 54 counties. This represents about 12 percent of the total acreage (764,000 acres; Borgeson, 1979) of inland lakes greater than five acres. Management Policy In 1971, Michigan's present muskellunge management policy was formulated (Robertson, 1971). Purebred muskellunge would be cultured primarily for the purpose of maintaining broodstock in natural waters. The bulk of the production effort would be aimed at hybrids for maintenance stocking purposes. Production goals were set at 10,000 to 20,000 purebred fingerlings and 100,000 hybrids annually. In 1976, these production levels were finally reached (Table 2). Because of increased demands for more tiger musky, the present production goal is 150,000 annually. Tiger musky are planted in suitable, strategically located lakes primarily to provide a trophy fishery. Like the pure strains, they add excitement, variety, and quality to overall fishing opportunities wherever they exist. They are planted annually or biennually at a rate of two to four fingerlings per surface acre. Managers do not expect them to control panfish abundance, but they are useful in maintaining desirable population balances. GROWTH IN THE WILD Beyerle (1978) reported on growth of tiger musky in Round Lake, Van Buren County. Age 0 fish reached 11.5"; Age I, 21.8"; Age II, 28.8" Age III, 33.6" and Ave IV, 37.0". Such growth rates are probably optimal and attainable only in the most fertile waters, primarily in southern Michigan. It is clear, however, that in most waters tiger musky reach legal size (30 inches) in either the third or fourth summer of their life (two or three years after planting). Fisheries managers rated tiger musky growth in 38 of 68 lakes surveyed (Table 3). Growth was rated fair or poor in only 12 (17.6%) of the lakes, while it was rated good to excellent in 26 (38%). Thirty lakes (44%) were not rated since many of these waters have only recently been stocked and data is not yet available. Table 3. Summary of ratings of 68 lakes managed for tiger muskellunge (Source: Unpublished data compiled from district fisheries reports, 1980). Number (%) Of Lakes Fishing Public Rating Scale Growth Survival Success Acceptance Poor 2 (2.9) 5 (7.4) 10 (14.7) 2 (2.9) Fair/Low 10 (14.7) 7 (10.3) 12 (17.6) 4 (5.9) Good/Mixed 21 (30.9) 18 (26.5) 11 (16.2) 37 (54.5) Very Good/High 3 (4.4) 4 (5.9) 2 (2.9) 7 (10.3) Excellent 2 (2.9) 2 (2.9) 4 (5.9) 6 (8.8) No Comment 30 (44.2) 32 (47.0) 29 (42.7) 12 (17.6) TOTAL 68 (100) 68 (100) 68 (100) 68 (100) I -8 - SURVIVAL IN THE WILD Evidence gathered to date indicates that the survival and growth of planted tiger musky is intermediate to that of both parents (Beyerle, 1973). Schrouder (1973) expected survival to Age IV (legal size) to be about 25 percent. Beyerle (1978) studied fry vs fingerling plants and pellet-reared vs minnow-reared hybrids. He reported survival rates for pellet-reared fingerlings to be 13.2 percent to Age 0 (11.5") and 10.2 percent for Age I (21.8"). Minnow-reared hybrids planted as fingerlings exhibited a survival rate of 25 percent for Age II fish (28.8") without fishing mortality. After one year of fishing, 5.3% of the Age III (33.6") hybrids survived. Fisheries managers rated tiger musky survival in 36 of 68 lakes surveyed (Table 3). In only 12 (18%) was survival rated as fair or poor. Twenty-four (35%) were rated as good to excellent and 32 (47%) were not rated. Generally speaking, managers found it difficult to evaluate survival rates because of the low population densities arising from our policy of planting at a rate of 2-4 fish per acre. In addition, many managers believe a significant portion of any population is harvested before the fish reach legal size (30"). In those waters where anglers are accustomed to keeping 20-inch northern pike, it is not surprising that they would choose to retain 25- to 30-inch tiger musky. FOOD HABITS Food habits of purebred muskellunge have been reported by many investigators and summarized by Schrouder (1973). After yolk absorption, they feed on small zooplankton for four to 10 days, then begin to feed on small fish. Soft-rayed fishes are preferred but as with other top predators, musky are opportunists and feed on those items of the appropriate size which are the most abundant or more easily captured. Information on diet of tiger muskellunge was secured from 19 of 68 lakes being managed for this species. Panfish (bluegills and pumpkinseed sunfish) were the food items most frequently observed in stomachs, followed by yellow perch, suckers, minnows, and goldfish. In every case, the food items observed reflected the most abundant forage species present in the lake. Information on fish taken in the winter showed most stomachs were void of any food items, indicating tiger musky feed very little during this season. SPORT FISHERY AND COST BENEFITS Tiger muskellunge are an often sought trophy, which requires a significant amount of time and effort to insure success. Behavior is similar to their purebred parents with respect to habitat preferences, yet they are more easily taken than purebred muskellunge in most waters. Williams (1959) reported that it took anglers with guides 26 hours to catch one purebred muskellunge, but that inexperienced anglers required 226 hours. On the other hand, Schrouder (1973) estimated that it took only about 20 hours to catch one tiger muskyo Jamsen (1979) and Beyerle (1979) reported that 25,000 anglers spent 240,000 anglerdays to catch 10,000 minnow reared hybrid muskies in 1977. This represented about two-thirds of the total statewide catch of all muskellunge and a return to the angler of about 25 percent of the stocked fish. - 9 - The value of the tiger muskellunge program can be estimated from Talhelm (1981) who indicated warmwater anglers would spend about $12.63 per angler-day with an economic impact twice the expenditure. Thus, based on the 1977 study, anglers would have expended $3,031,000 during the 240,000 angler-days fished, resulting in an economic impact of over $6 million. It is presently estimated that the cost of rearing a tiger musky on pelleted food to planting size (6 inches) is about 11.3~ each (Westers, personal communication). Considering an annual production of 150,000 fingerlings and a 25 percent return of pellet-reared fish to the angler, (Beyerle, personal communications) the annual rearing cost of the program (excluding research and evaluation) is about $17,000, or about $2.27 per fish in the creel. Opportunities to catch tiger muskellunge are fairly well distributed statewide (Figure 4). A total of 141 inland lakes in 54 of Michigan's 83 counties have been stocked with the hybrid. Of the 95,177 acres being managed for tigers, one-third are located in each of the three regions; however, 66 (47%) of the lakes are located in southern lower Michigan. A survey of licensed anglers in 1977 indicated that 7% rated northern pike or muskellunge as their preferred sport fish (Jamsen, 1979). By comparison, 21% selected bass as their first choice, and 13% selected walleye. Panfish were the first choice of 17% of the anglers surveyed. During 1980, Fisheries managers reviewed fishing success from 68 of the 141 managed lakes (Table 3). Seventeen (25%) of the 68 lakes were considered to have good to excellent fishing while 22 (32%) had fair to poor. No information was available on the remaining 29 lakes. IMPACT ON FISH POPULATIONS AND PUBLIC ACCEPTANCE Fisheries managers also assessed the impact of the tiger musky program on 24 of 68 stocked lakes. In 20 of the 24, tiger musky were judged to have no impact on the remaining fish community. One lake was judged to have more largemouth bass after musky introduction than before, however, this may have been due in part to other management practices. One lake was judged to have fewer panfish; one, fewer pech; and one, fewer small panfish than before introduction of tiger muskies. One biologist cited two lakes where reliable anglers perceived a decline in largemouth bass abundance. He speculated that if a decline was real, it was more apt to be due to displacement from preferred habitat rather than due to predation. Beyerle (1980) reviewed a similar 1977 field evaluation of lakes managed for tiger musky. The review concluded that tiger muskies did not affect the number or size of panfish (in 12 lakes studied), or largemouth bass (in 5 lakes studied), but did compete with northern pike (in 4 lakes studied). In one lake where spearing was banned, the pike population increased. One lake fish population may have been adversely affected by the introduction of purebred northern muskellunge. Iron Lake, Iron County, developed an exceptionally large population of northern musky resulting from 10 years of stocking (1962-1973), abundant natural reproduction, a restrictive size limit (36 inches) and a protective spearing ban. Abundance and size of black crappie, largemouth and smallmouth bass, - 10 6;ý.3 2788 9 Region I Region II Region III TIGER MUSKY N umber 44 31 66_ 141 LAKES Acres 29,1621 33,660 31,9896 95,177 4'ý 5895 igure SEIRIEN I4 1 2 ICLS IT.JSEH NC NHILSDALE' LENAWEE MONROE 600 76 1588 3270 414 2110 Distribution of inland lakes stocked with tiger muskellunge from 1966-1980. Number of lakes (above) and total acres (below) are indicated. - 11 - and suckers decreased dramatically. It is unlikely, however, that tiger muskellunge would cause similar problems because their abundance can be controlled by reducing or eliminating the stocking program in any given lake. Public acceptance of the tiger musky program was also rated during 1980. Fifty of the 68 lakes (74%) reviewed by biologists were rated as good to excellent (Table 3). Acceptance was poor to fair on only six lakes (less than 9%). Opposition to a tiger musky program usually was associated with fears of imposition of a spearing ban, or concern for other fish species. Areas of poor acceptance were centred around Iron and Chicagoan lakes (Iron County), some Grand Lake (Presque Isle County) residents, and Crooked Lake (Barry County). Public support has been voiced for expanding the tiger musky program in several areas of the state. These include the eastern and western ends of the Upper Peninsula and the Mio and Jackson fish management districts. In several districts, especially in Region III, tiger muskellunge are second only to walleye in requests for fish to be planted. LITERATURE CITED Beyerle, G.B. 1973. Comparative growth, survival, and vulnerability to angling of northern pike, muskellunge, and the hybrid tiger muskellunge stocked in a small lake. MDNR, Fisheries Div. Res. Rep. No. 1799. 11 pp. Beyerle, G.B. 1978. The value of tiger musky fingerlings to fisheries management in Michigan. pp. 137-144. In Annual Reports, Dingell-Johnson Project F-35-R-4 (Study Group 2). Beyerle, G.B. 1979. Ibid. pp. 65-72. In Annual Reports, Dingell-Johnson Project F-35-R-5 (Study Group 2). Beyerle, G.B. 1980. Ibid. ppo 43-59 and 73-74. In Annual Reports, DingellJohnson Project F-35-R-6 (Study Group 2). Borgeson, D.P. 1979. Michigan's inland fisheries management program. Unpblo 10 pp. Graff, D.R. 1978. Intensive culture of esocids: The current state of the art. A.FoS. Spec. Publ. No. 11:195-201. Jamsen, G.C. 1979. Michigan's 1977 muskellunge sport fishery. M.D.N.R. Surveys and Statistical Service Report No. 197, Unpbl. 4 pp. Robertson, J.R. 1971. Production objectives: Proposed warmwater hatchery. M.D.N.R. Fish. Div. Report No. 18. Unpbl. 10 pp. Schrouder, J.D. 1973. Muskellunge management in Michigan. M.D.N.R. Fish. Div. Tech. Rep. 73-31. 21 pp. Scott, J.A. 1963. A synopsis of muskellunge culture and manaaement in Michigan. Unpbl. Report. 3 pp. - 12 -Scott, W.B. and E. J. Crossman. 1973. Freshwater fishes of Canada. Fish. Res. Bd. of Canada Bull. 184. pp. 363-369 Talhelm, D.R., et. al. 1981. The role of fish and wildlife in Michigan's economy. Mich. Nat. Res. Outlook Conf., Unpbl. 37 pp. Williams, J.E. 1959. The muskellunge in Michigan. Mich. Dept. of Cons., Fish. Div. Pamphlet No. 30. 5 pp.